Wireless communication network and transceiver

Abstract

A radio transmitting device configured to transmit a spread-spectrum radio signal wherein a carrier frequency changes in a predetermined set of radio channels according to a hopping sequence, the radio signal being organized in packets having each a header transmitted at a first channel in the hopping sequence comprising a detection sequence, and payload data encoding a message transmitted at following channels in the hopping sequence.

The invention claimed is: 
     
       1. A radio transmitting device configured to transmit a spread-spectrum radio signal wherein a carrier frequency changes in a predetermined set of radio channels according to a hopping sequence, the spread-spectrum radio signal being organized in packets having each a header transmitted at a first channel in the hopping sequence comprising a detection sequence, and payload data encoding a message transmitted at following channels in the hopping sequence further configured to select a binary mask and generate the hopping sequence by generating a pseudorandom permutation of numbers, alter the pseudorandom permutation by bitwise exclusive-or operations with the binary mask, reduce a range of the altered permutation such that the range is contained in the predetermined set of radio channels, encoding the binary mask in the header to announce the hopping sequence. 
     
     
       2. The radio transmitting device of  claim 1 , wherein the packets have redundant headers announcing the hopping sequence transmitted at different channels. 
     
     
       3. The radio transmitting device of  claim 1 , configured to shuffle the bits of the hopping sequence. 
     
     
       4. The radio transmitting device of  claim 1 , configured to generate the pseudorandom permutation of numbers with a maximal-length linear feedback shift register (LFSR), wherein a feedback function of the LFSR is encoded in the header. 
     
     
       5. The radio transmitting device of  claim 1 , wherein the reduction of the range to the predetermined set of radio channels consists in skipping values that are not in the set of channels or in inserting silences when values are not in the set of channels. 
     
     
       6. The radio transmitting device of  claim 1 , wherein the alteration of the pseudorandom permutation is an exclusive-or of a status of the LFSR with the binary mask, provided the status of the LFSR is not equal to the binary mask, followed by a decrement by one. 
     
     
       7. The radio transmitting device of  claim 1 , wherein the alteration of the pseudorandom permutation is appending a zero value at a predetermined position in the sequence followed by an exclusive-or of a status of the LFSR with the binary mask. 
     
     
       8. The radio transmitting device of  claim 1 , wherein the binary mask is chosen in such a way that no channel in first subset of contiguous channels at the beginning of the hopping sequence appears in the same subset of channels of a hopping sequence of an immediately preceding packet. 
     
     
       9. The radio transmitting device of  claim 8 , wherein the header or the redundant headers have a dwell time at the respective channels that is longer than a dwell time of payload data. 
     
     
       10. The radio transmitting device of  claim 8 , wherein the binary mask has a predetermined offset from a binary mask chosen for the immediately preceding packet. 
     
     
       11. The radio transmitter of  claim 1 , wherein the hopping sequence includes two nested sequences, being an outer sequence and an inner sequence, the outer sequence being the sequence generated by altering the pseudorandom permutation by bitwise exclusive-or operations with the binary mask and reducing a range of the altered permutation in the predetermined set of radio channels, the inner sequence being a sequence of constant predetermined increments. 
     
     
       12. The radio transmitting device of  claim 11 , wherein the outer sequence has a range that is a proper subset of the predetermined set of radio channels, and the inner sequence is chosen such that the hopping sequence uses all the radio channels.